In this technical field, methods and apparatuses which enable the integration of the production of the tire reinforcements in the assembly of the tire itself are already known. This means that, rather than resorting to semi-finished products, such as reinforcement plies, one or more reinforcements are constructed in situ at the time the tire is produced, and from a single thread reel. Among these methods and apparatuses, the solution described in U.S. Pat. No. 5,616,209 is very particularly suitable for the construction of carcass reinforcements on a rigid core, the outer surface of which corresponds substantially to the form of the inner cavity of the final tire. The '209 patent discloses an apparatus in which the thread intended to form a carcass reinforcement is laid in contiguous hoops on a rigid core by an eyelet fixed on a chain mounted on pulleys so as to surround the core by forming a kind of “C” shape. The eyelet performs a to-and-fro movement about the core so as to lay, progressively and contiguously, one hoop on each outward journey and one hoop on each return journey, with the intervention of appropriate pressers for applying the ends of the hoops to the rigid core, precoated with crude rubber, in the process.
An apparatus likewise provided for the construction of carcass reinforcements on a rigid core, the outer surface of which corresponds substantially to the form of the inner cavity of the final tire, is known from the European Patent Application EP 0 962 304. This document discloses, in a first embodiment, a single oscillating arm, the end of which, supporting a guiding member comparable to the eyelet mentioned above, necessarily describes circular arcs. Reference may be made to FIG. 3 of the Patent Application EP 0 962 304.
With a single oscillating arm as proposed in the Patent Application EP 0 962 304, however, it is not possible to bring the thread sufficiently near to the laying zone in each of the beads. The presser devices used on either side of the core to take hold of the thread and press it against the core consequently operate with a fairly long stroke. The farther the bead is axially set back with respect to the point of the sidewall corresponding to the maximum axial width of the core, the longer the stroke of the presser devices. Apart from the fact that this might pose problems with the laying precision, the construction of the pressers is thereby rendered more awkward.
The object of the present invention is to propose an apparatus capable of operating according to the general method described in the above-mentioned U.S. Pat. No. 5,616,209, and capable of operating at considerable rates without having a detrimental effect on the operating precision.